Cardiovascular suite for the imposition and assessment of physiological stressors

运动是一种常见的影响多器官系统的生理应激源，为研究人体内稳态和适应所涉及的心血管反应和其他反应提供了一个有价值的模型。重要的是，心脏有效泵血的能力也可能受到其他常见应激源(如高温、海拔、大麻使用)的影响，这些应激因素可能与运动施加的压力相互作用。因此，在这些条件下测量心输出量对于了解正常的运动生理学及其在改善人类生活方面的应用--从临床应用到运动表现和军事活动到太空旅行--是极其重要的。然而，在剧烈运动期间，使用标准的成像方法测量心输出量可能很困难，而且临床替代方法具有高度侵入性或昂贵得令人望而却步。这笔赠款要求资金购买惰性气体再呼吸系统，以非侵入性地测量休息和运动期间的心输出量，以及购买环境运动室，以研究运动期间热、低氧应激和大麻使用对心血管功能的影响。该设备代表了行业领先的技术，将满足申请者研究计划中的一项关键和迫切需求，即1)运动期间心输出量的准确和可靠测量，以及2)检查常见环境应激源对运动期间心输出量的额外影响。这些设备的使用将支持由NSERC资助的U Guelph和McMaster的前沿研究和培训计划。伯尔博士的实验室需要这种设备来跟进新的发现，即运动期间限制腿部的血液流动会导致吸收和使用氧气进行肌肉工作的能力增强，这一发现出人意料，但尚未得到解释。它还将推动显示运动和环境特有的心脏对运动的适应的研究。米勒博士的团队要求惰性气体再呼吸系统在重要工作上有所扩展，以了解运动过程中血压反应的性别差异，以及不同强度的运动对血管和心输出量的交感神经控制的不同如何调节血压。惰性气体再呼吸系统对Gibala博士的工作也至关重要，他要了解不同的运动暴露是如何改变心输出量、血液和骨骼肌的氧气输送的。最后，Burr和Millar博士需要密封舱和惰性气体再呼吸装置来支持他们开创性和及时地研究运动期间大麻对心血管功能的影响。申请者培训了一个由28名总部合格人员组成的多样化群体，他们目前因无法获得这种设备而受到阻碍。所要求的项目将极大地扩展我们的研究能力，包括更多的用户，可能会对&gt；50总部产生积极的好处，同时支持跨机构的合作研究。

Exercise is a common physiological stressor that affects multiple organ systems, providing a valuable model to study cardiovascular and other responses involved in homeostasis and adaptation in humans. Importantly, the ability of the heart to effectively pump blood can also be affected by other common stressors (e.g., heat, altitude, cannabis use) that can interact with the stresses imposed by exercise. Measuring cardiac output under these conditions is thus incredibly important for understanding normal exercise physiology and its applications to improving human life- from clinical applications to sport performance and military activities to space travel. However, measurements of cardiac output can be difficult to perform during intense exercise using standard imaging practices, and clinical alternatives are highly invasive or prohibitively expensive. This grant requests funds to purchase an inert gas rebreathe system to non-invasively measure cardiac output at rest and during exercise, and an environmental exercise chamber to study the effects of thermal and hypoxic stress and cannabis use on cardiovascular function during exercise. This equipment represents industry leading technologies that will fulfill a critical and urgent need in the applicants' research programs for 1) accurate and reliable measurements of cardiac output during exercise, and 2) examining the additional effects of common environmental stressors on cardiac output during exercise. Access to this equipment will support leading-edge NSERC-funded research and training programs at both U Guelph and McMaster. Dr. Burr's lab requires the equipment to follow-up on novel findings that blood flow restriction to the legs during exercise causes unexpected, and yet unexplained, augmentation of the ability to take up and use oxygen to perform muscular work. It will also advance research that shows sport- and environment-specific cardiac adaptations to exercise. Dr. Millar's group requires the inert gas rebreathing system to expand on important work understanding the sex differences in blood pressure response during exercise, and how blood pressure is modulated by differences in sympathetic control of vascular and cardiac output through differing intensities of exercise. The inert gas rebreathing system is also crucial to Dr. Gibala's work understanding how various exposures to exercise alter cardiac output, blood, and oxygen delivery to skeletal muscle. Finally, Drs Burr and Millar require both the enclosed chamber and the inert gas rebreathing device to support their pioneering and timely work examining the effects of cannabis on cardiovascular function during exercise. The applicants train a diverse group of 28 HQP who are currently hindered by a lack of access to this equipment. The requested items will greatly expand our research capacity and, including additional users, could positively benefit >50 HQP while supporting collaborative research across institutions.